1. Field of the Invention
The present invention relates to cellular telephones and, more particularly, to a system for using a cellular telephone without producing potentially hazardous radiation near the body of users.
2. Description of the Prior Art
Cellular phones are becoming omnipresent and necessary elements as society enters the new millennium. Unfortunately, operating on radio frequency transmission, these are also sources of electromagnetic radiation. Most phones include an antenna that is placed close to the user""s head, emitted radiation and suspected to be hazardous to users. Attempts to reduce the emitted radiation by placing a shield around the antenna, have been found to be impractical and thus have not been commonly employed in cellular telephones. Another proposed solution is to avoid placing the antenna near the head of the user. Proposed and now commonly available is an electrical wire that is connected to the telephone at the input/output port of the cellular phone and terminating with an earpiece that is placed in the user""s ear. A microphone is mounted on the wire near the earpiece, putting it at the level of the mouth of the user when the earpiece is placed in the ear. In such an arrangement, the telephone may be clipped to a user""s belt or placed in a pocket or a purse, with the wire extending therefrom. The earpiece is placed in the user""s ear.
When the user receives or makes a telephone call, the user merely activates the xe2x80x9csendxe2x80x9d or similar button on the cellular telephone to complete the call hands free. The user hears through the earpiece, the other party hearing the user through the signal picked up by the microphone which is in proximity of the mouth. Another configuration of cellular telephones in use includes a loudspeaker coupled directly to and mounted on a cellular telephone. The user can hear the emitted sounds with no need to hold the cellular telephone close to head. However, since a loudspeaker is used instead of a microphone, privacy is denied unless the user is alone.
Not only do these solutions provide for hands free operation of the telephone, they were also believed to have resolved the problem of unwanted radiation near the user""s head, the telephone being remote therefrom. Unfortunately, recent studies conducted in Britain in 2000 have shown that such a wire configuration does not reduce radiation near the user""s head.
There have been number of attempts aimed at solving the problem of potentially hazardous radiation emitted from cellular telephones.
U.S. Pat. No. 4,090,042 relates to acoustical communications headset including tubes for the transmission of sound.
U.S. Pat. No. 5,528,689 relates to a method for converting a cellular telephone into a headset telephone. U-shaped clips are used for attaching a mouth cup and an ear cup to the cellular telephone. However, there is still a problem that might evolve from disposition of these cups. Such disposition will interfere significantly with the smooth operation of the cellular telephone, since too much noise from the surroundings might be picked up by the microphone, or alternatively mask the sound coming from the earpiece. In addition, headset adjustment to user""s head is done by a complicated mechanism that may easily dismembered.
U.S. Pat. No. 5,613,222 relates to a hands-free cellular phone that employ acoustical tubes. A receiving cup is attached to the speaker of the cellular telephone by loop type Velcro fasteners. However, Velcro straps can still be bulky and accidentally detached. Such disposition will interfere significantly with smooth operation of the cellular telephone, since too much ambient noise from surrounding might be picked up by the microphone.
While these devices fulfill their particular objectives and requirements the aforementioned devices are not effective when the telephone has to be located more than ten feet away from the user, since longer acoustical tubes absorbs too much noise from surroundings.
In addition, receiving and transmitting of sound waves between the cellular phone and the user is not mediated by any apparatus capable of amplifying, coding, decoding, filtering, or conferring any other change on the sounds heard or spoken. Such apparatus, hereafter called a conversion device, is required especially when using the cellular phone near a source of loud noise. There is therefore a need for producing a cellular telephone employing acoustical tubing that can be employed in a noisy environment.
The present invention relates to cellular phone systems which use acoustical tubes for the transmission of sound. The present invention successfully addresses the shortcomings of the prior art by transmitting sound signals between the telephone and earpiece or microphone via a combination of electrical wire and acoustical tube connected end to end by a novel conversion device.
This conversion device may be connected to any kind of electrical output of mobile telephones and other apparatus. Hence, there is no need to make any changes in the configuration of existing mobile telephone in order to use this system.
In these respects, the present invention substantially departs from the conventional concepts and designs of the prior art, and in so doing provides an apparatus primarily developed for the purpose of communicating near loud noise sources.